barebox - rk3568

[Sascha Hauer]

Hi Frank,

On Tue, Jan 04, 2022 at 09:39:05AM +0100, Frank Wunderlich wrote:
> Hi,
> 
> i have a prototype rk3568 board (bpi-r2-pro).
> 
> is it possible to flash only barebox instead of uboot? in documentation i found only "creating SD-card", but i dont want to break existing partitions.

The rk3568 has a fixed boot order of eMMC, SD, USB. The EVB board has a
pushbutton to shortcircuit a pin of the eMMC. When pushed, the eMMC
becomes invalid and the board boots from SD card. I could imagine it's
the same on your board, so you could create an SD card and boot from
that. Other than that an image that starts from SD card can also start
from eMMC, the images are the same.
You could also start from USB, the barebox tree has a rk3568 USB loader
tool.

> 
> https://www.barebox.org/doc/latest/boards/rockchip.html#rockchip-rk3568
> 
> says it starts from sector 32, my first block for uboot (idblock.bin=spl+raminit) starts at 64, full uboot in partition at 8M.
> 
> As it differs a bit from evb can i add new dts like in uboot?

Yes, you can. See
https://www.barebox.org/doc/latest/devel/porting.html?highlight=new%20board
for more information how. Also have a look at commit b9f1bb8563ba
which adds the EVB board support. You'll have to do the same for your
board.
One thing you'll need is a sdram-init.bin file. You can extract it from
your BSP.

Regards,
  Sascha

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